4. History of transplantation or currently on lung transplant list 5. Positive serum pregnancy test at screening (to be performed on all post-menarche females) 6. Pregnant, breastfeeding, or if post-menarche female, unwilling to practice birth control during participation in the study 7. Presence of a condition or abnormality that in the opinion of the site investigator would compromise the safety of the subject or the quality of the data 8. Diagnosis of HIV and a CD4+ T cell count below 500 cells/ml or active hepatitis B or C infection.